Spreadwatch
Crypto price gaps across exchanges and Solana, live
Follow any crypto asset on Binance, Bybit, OKX, MEXC, Gate and Jupiter at once. See the best cross-venue edges net of fees, which venue's price trails the others, and the tokens Gate or MEXC just listed that Binance does not have yet. Swap SOL/USDT on-chain through Jupiter from a local hot wallet, in a dry run at every start and within hard limits.
Free for personal, educational and non-profit use. Commercial use — including a solo consultant on client work — requires a licence. Every build is produced by release CI and served from mayorana.ch.
The macOS build is signed with an Apple Developer ID and notarized, so it opens with a normal double-click.
Read the release notesThis app is in beta. The core workflow is stable; some panels are still being refined.
Overview
The same token trades on a dozen venues at slightly different prices, and the gap moves every second. Watching it means five exchange tabs, a DEX aggregator and a spreadsheet, and by the time the numbers are side by side they are stale.
Spreadwatch streams the order books of Binance, Bybit, OKX, MEXC and Gate, and polls Jupiter for Solana tokens, into one window. It shows the best buy-here, sell-there route in basis points, gross and net of the taker fee on both legs, and measures which venue's price tends to move last.
A second tab scans for tokens Gate or MEXC just listed against USDT that Binance spot does not list, and scores how serious each looks. For SOL/USDT, the app can also swap on-chain through Jupiter from a hot wallet it creates, signed on your machine.
What it does
One watchlist, six venues
Add any ticker (BTC, ETH, JUP, BONK…) and see its best bid and ask on Binance, Bybit, OKX, MEXC and Gate, plus Jupiter for Solana tokens, with a warning when a feed goes stale.
Edges net of fees
Every buy-on-one, sell-on-another route ranked in basis points, gross and after the taker fee on both legs, so a gap that fees would eat is shown for what it is.
Who is late
Measures, venue by venue, how many milliseconds its price trails the others on average — the venue that moves last is where a gap opens first.
New listings before Binance
Tokens Gate or MEXC listed in the last few days, or have scheduled, that Binance spot does not list, scored by volume, other listings, market cap and whether Binance already follows them through futures or Alpha.
On-chain swaps with guardrails
SOL/USDT swaps through Jupiter from a hot wallet the app creates. It starts in dry run every time, asks before going live, and enforces per-trade, daily, slippage and priority-fee limits a settings file can lower but never raise.
Requirements
- macOS 11 or later (Apple Silicon or Intel), Windows 10 or 11 with the WebView2 Runtime, or Linux x86_64 (Ubuntu 22.04+, Debian 12+, current Fedora and Arch)
- An internet connection: prices come from the exchanges' public APIs, no exchange account needed
- For on-chain trading only: SOL in the app's hot wallet, and preferably a Solana RPC provider URL
Built with
Rust · Dioxus · WebSockets · Solana · Jupiter
What's new
Version 0.1.3, released 27 September 2026. Spreadwatch ships often; every version and what it changed is listed on the release notes page.
Read the release notesLicence
Source-available under the PolyForm Noncommercial License 1.0.0: free for personal use, learning, research and hobby projects, and for charities, schools, universities and government institutions. Companies using it for work buy a licence.
Source
The source is public and readable. Fork it and rebrand it — the name and logo are trademarks and are not covered by the licence.
View on GitHubQuestions
Do I need accounts or API keys on the exchanges?
No. Prices come from the exchanges' public market data. Trading only happens on-chain through Jupiter, from the app's own wallet.
Is a spread on screen a profit?
No. The net figure subtracts taker fees, but not transfer times, withdrawal fees and limits, slippage or the price moving while you act. Spreadwatch shows where to look, not what you will earn. It is not financial advice.
Where is my wallet key kept?
In a file in the app's settings folder that only your user account can read, and nowhere else. Back it up: it is the only copy, and anyone who gets it can spend from the wallet.
Need it adapted to your work?
Each of these tools is built and maintained by us. If you need a variant — a different data source, your own conventions, a feature your team is missing, an on-prem build — that is the kind of work we take on.
Get in touch